/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.zeppelin.iotdb;

import org.apache.commons.lang3.StringUtils;
import org.apache.iotdb.jdbc.Config;
import org.apache.iotdb.jdbc.IoTDBConnection;
import org.apache.iotdb.jdbc.IoTDBJDBCResultSet;
import org.apache.iotdb.rpc.IoTDBConnectionException;
import org.apache.iotdb.rpc.RpcUtils;
import org.apache.iotdb.rpc.StatementExecutionException;
import org.apache.thrift.TException;
import org.apache.zeppelin.interpreter.AbstractInterpreter;
import org.apache.zeppelin.interpreter.InterpreterContext;
import org.apache.zeppelin.interpreter.InterpreterResult;
import org.apache.zeppelin.interpreter.InterpreterResult.Code;
import org.apache.zeppelin.interpreter.InterpreterResult.Type;
import org.apache.zeppelin.interpreter.ZeppelinContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.sql.*;
import java.time.ZoneId;
import java.util.*;

import static org.apache.iotdb.rpc.IoTDBRpcDataSet.TIMESTAMP_STR;
import static org.apache.iotdb.rpc.RpcUtils.setTimeFormat;

public class IoTDBInterpreter extends AbstractInterpreter {

    private static final Logger LOGGER = LoggerFactory.getLogger(IoTDBInterpreter.class);

    static final String IOTDB_HOST = "iotdb.host";
    static final String IOTDB_PORT = "iotdb.port";
    static final String IOTDB_USERNAME = "iotdb.username";
    static final String IOTDB_PASSWORD = "iotdb.password";
    static final String IOTDB_FETCH_SIZE = "iotdb.fetchSize";
    static final String IOTDB_ZONE_ID = "iotdb.zoneId";
    static final String IOTDB_ENABLE_RPC_COMPRESSION = "iotdb.enable.rpc.compression";
    static final String IOTDB_TIME_DISPLAY_TYPE = "iotdb.time.display.type";
    private static final String NONE_VALUE = "none";
    static final String DEFAULT_HOST = "127.0.0.1";
    static final String DEFAULT_PORT = "6667";
    static final String DEFAULT_FETCH_SIZE = "10000";
    static final String DEFAULT_ENABLE_RPC_COMPRESSION = "false";
    static final String DEFAULT_TIME_DISPLAY_TYPE = "long";
    static final String DEFAULT_ZONE_ID = "UTC";
    static final String NULL_ITEM = "null";

    private static final char TAB = '\t';
    private static final char NEWLINE = '\n';
    private static final char WHITESPACE = ' ';
    private static final String SEMICOLON = ";";
    private static final String EQUAL_SIGN = "=";

    /**
     * should be consistent with IoTDB client
     */
    private static final String QUIT_COMMAND = "quit";

    private static final String EXIT_COMMAND = "exit";
    private static final String HELP = "help";
    private static final String IMPORT_CMD = "import";
    static final String SET_TIMESTAMP_DISPLAY = "set time_display_type";
    private static final String SET_MAX_DISPLAY_NUM = "set max_display_num";
    private static final String SHOW_TIMESTAMP_DISPLAY = "show time_display_type";
    private static final String SET_TIME_ZONE = "set time_zone";
    private static final String SHOW_TIMEZONE = "show time_zone";
    private static final String SET_FETCH_SIZE = "set fetch_size";
    private static final String SHOW_FETCH_SIZE = "show fetch_size";

    private static final Set<String> nonSupportCommandSet =
            new HashSet<>(
                    Arrays.asList(
                            QUIT_COMMAND,
                            EXIT_COMMAND,
                            HELP,
                            IMPORT_CMD,
                            SET_TIME_ZONE,
                            SET_FETCH_SIZE,
                            SET_MAX_DISPLAY_NUM,
                            SHOW_TIMEZONE,
                            SHOW_TIMESTAMP_DISPLAY,
                            SHOW_FETCH_SIZE,
                            IMPORT_CMD));

    private String timeFormat;

    private IoTDBConnectionException connectionException;
    private IoTDBConnection connection = null;
    private int fetchSize;
    private ZoneId zoneId;

    public IoTDBInterpreter(Properties property) {
        super(property);
    }

    @Override
    public void open() {
        String host;
        int port;
        String passWord;
        try {
            host = getProperty(IOTDB_HOST, DEFAULT_HOST).trim();
            port = Integer.parseInt(getProperty(IOTDB_PORT, DEFAULT_PORT).trim());
            userName = properties.getProperty(IOTDB_USERNAME, NONE_VALUE).trim();
            passWord = properties.getProperty(IOTDB_PASSWORD, NONE_VALUE).trim();
            this.fetchSize =
                    Integer.parseInt(properties.getProperty(IOTDB_FETCH_SIZE, DEFAULT_FETCH_SIZE).trim());

            String timeDisplayType =
                    properties.getProperty(IOTDB_TIME_DISPLAY_TYPE, DEFAULT_TIME_DISPLAY_TYPE).trim();
            this.timeFormat = setTimeFormat(timeDisplayType);
            Config.rpcThriftCompressionEnable =
                    "true"
                            .equalsIgnoreCase(
                                    properties
                                            .getProperty(IOTDB_ENABLE_RPC_COMPRESSION, DEFAULT_ENABLE_RPC_COMPRESSION)
                                            .trim());

            Class.forName(Config.JDBC_DRIVER_NAME);
            this.connection =
                    (IoTDBConnection)
                            DriverManager.getConnection(
                                    Config.IOTDB_URL_PREFIX + host + ":" + port + "/", userName, passWord);
            String zoneStr = properties.getProperty(IOTDB_ZONE_ID);
            if (!NONE_VALUE.equalsIgnoreCase(zoneStr) && StringUtils.isNotBlank(zoneStr)) {
                this.zoneId = ZoneId.of(zoneStr.trim());
                connection.setTimeZone(zoneStr);
            } else {
                this.zoneId = ZoneId.systemDefault();
                connection.setTimeZone(this.zoneId.getId());
            }
            connection.setTimeZone(this.zoneId.getId());

        } catch (SQLException | ClassNotFoundException | TException e) {
            connectionException = new IoTDBConnectionException(e);
        }
    }

    @Override
    public void close() {
        try {
            if (this.connection != null) {
                this.connection.close();
            }
        } catch (SQLException e) {
            connectionException = new IoTDBConnectionException(e);
        }
    }

    @Override
    public FormType getFormType() {
        return FormType.SIMPLE;
    }

    @Override
    public ZeppelinContext getZeppelinContext() {
        return null;
    }

    @Override
    public InterpreterResult internalInterpret(String st, InterpreterContext context) {
        if (connectionException != null) {
            return new InterpreterResult(
                    Code.ERROR, "IoTDBConnectionException: " + connectionException.getMessage());
        }
        try {
            String[] scriptLines = parseMultiLinesSQL(st);
            InterpreterResult interpreterResult = null;

            for (String scriptLine : scriptLines) {
                interpreterResult = handleInputCmd(scriptLine, connection);
            }
            return interpreterResult;
        } catch (StatementExecutionException e) {
            return new InterpreterResult(Code.ERROR, "StatementExecutionException: " + e.getMessage());
        }
    }

    private InterpreterResult handleInputCmd(String cmd, IoTDBConnection connection)
            throws StatementExecutionException {
        String specialCmd = cmd.toLowerCase().trim();
        if (nonSupportCommandSet.contains(specialCmd)) {
            return new InterpreterResult(Code.ERROR, "Not supported in Zeppelin: " + specialCmd);
        }
        if (specialCmd.startsWith(SET_TIMESTAMP_DISPLAY)) {
            String[] values = cmd.split(EQUAL_SIGN);
            if (values.length != 2) {
                throw new StatementExecutionException(
                        String.format(
                                "Time display format error, please input like %s=ISO8601", SET_TIMESTAMP_DISPLAY));
            }
            String timeDisplayType = values[1].trim();
            this.timeFormat = setTimeFormat(values[1]);
            return new InterpreterResult(Code.SUCCESS, "Time display type has set to " + timeDisplayType);
        }
        return executeQuery(connection, cmd);
    }

    private InterpreterResult executeQuery(IoTDBConnection connection, String cmd) {
        StringBuilder stringBuilder = new StringBuilder();
        try (Statement statement = connection.createStatement()) {
            statement.setFetchSize(fetchSize);
            boolean hasResultSet = statement.execute(cmd.trim());
            InterpreterResult interpreterResult;
            if (hasResultSet) {
                try (ResultSet resultSet = statement.getResultSet()) {
                    boolean printTimestamp =
                            resultSet instanceof IoTDBJDBCResultSet
                                    && !((IoTDBJDBCResultSet) resultSet).isIgnoreTimeStamp();
                    final ResultSetMetaData metaData = resultSet.getMetaData();
                    final int columnCount = metaData.getColumnCount();

                    for (int i = 1; i <= columnCount; i++) {
                        stringBuilder.append(metaData.getColumnLabel(i).trim());
                        stringBuilder.append(TAB);
                    }
                    deleteLast(stringBuilder);
                    stringBuilder.append(NEWLINE);
                    while (resultSet.next()) {
                        for (int i = 1; i <= columnCount; i++) {
                            if (printTimestamp && i == 1) {
                                stringBuilder.append(
                                        RpcUtils.formatDatetime(
                                                timeFormat,
                                                RpcUtils.DEFAULT_TIMESTAMP_PRECISION,
                                                resultSet.getLong(TIMESTAMP_STR),
                                                zoneId));
                            } else {
                                stringBuilder.append(
                                        Optional.ofNullable(resultSet.getString(i)).orElse(NULL_ITEM).trim());
                            }
                            stringBuilder.append(TAB);
                        }
                        deleteLast(stringBuilder);
                        stringBuilder.append(NEWLINE);
                    }
                    deleteLast(stringBuilder);
                    interpreterResult = new InterpreterResult(Code.SUCCESS);
                    interpreterResult.add(Type.TABLE, stringBuilder.toString());
                    return interpreterResult;
                }
            } else {
                return new InterpreterResult(Code.SUCCESS, "Sql executed.");
            }
        } catch (SQLException e) {
            return new InterpreterResult(Code.ERROR, "SQLException: " + e.getMessage());
        }
    }

    private void deleteLast(StringBuilder stringBuilder) {
        stringBuilder.deleteCharAt(stringBuilder.length() - 1);
    }

    @Override
    public int getProgress(InterpreterContext context) {
        return 0;
    }

    @Override
    public void cancel(InterpreterContext context) {
        try {
            connection.close();
        } catch (SQLException e) {
            LOGGER.error("Exception close failed", e);
        }
    }

    public static String[] parseMultiLinesSQL(String sql) {
        String[] tmp =
                sql.replace(TAB, WHITESPACE).replace(NEWLINE, WHITESPACE).trim().split(SEMICOLON);
        return Arrays.stream(tmp).map(String::trim).toArray(String[]::new);
    }
}
